
Le 31
3" Solid Breathable Trunk Lenzing™ Ecovero™ Viscose
This men's trunk-style underwear from Le 31 by Simons is a low-rise, fitted garment with a 3-inch inseam. It is made from a LENZING™ ECOVERO™ viscose jersey fabric derived from certified renewable wood sources, featuring an elastic waistband and a double-layered front. Designed in Canada, it is breathable and suitable for everyday wear.
- Category
- Apparel & Accessories > Clothing > Underwear & Socks > Underwear
Color
Size
Specifications
- Material
- 92% LENZING™ ECOVERO™ viscose, 8% spandex
- Gender
- male
- Age Group
- adult
- Condition
- new
- Category
- Apparel & Accessories > Clothing > Underwear & Socks > Underwear
Product Insights
Le 31's 3-inch trunk in Lenzing Ecovero viscose is a traceable, EU-Ecolabeled, FSC/PEFC-certified knit that cuts water use and CO2 by at least 50% versus generic viscose, delivering a thinner, softer, cooler daily-wear layer that stays put and hides cleanly under shorts or slim trousers; its tradeoff is a lighter hold—buyers switching from the older bamboo trunk find it less durable, with pilling after washing and support too light for workouts—while the 3-inch leg avoids bunching but exposes inner thighs to chafing, and the waistband feels slightly loose by design. It absorbs moisture rather than wicking, so runs and heavy lifts risk friction; care is exacting: cold wash and flat air-dry keep shrinkage under 5%, hot washing or tumble drying can push it past 12%, and air-drying alone can take over a day. Colorway quirks matter too—Navy/Midnight Blue runs smaller and looks different in person, while only Citrus/Bright Orange is vivid; the rest are muted single-tone garments that stay opaque under stretch but visible under ultra-thin white, and dye colors read vividly on camera.
Verified claims
- Certifications
- ECOVERO fiber holds the EU Ecolabel, its wood is FSC/PEFC certified, and its producer tops Canopy's ranking
- Environmental impact
- ECOVERO fiber production is at least 50% lower in both water use and CO2 than generic viscose
- Traceability
- Molecular marker ensures full supply chain traceability from forest to garment
- Care
- Cold wash and flat air-dry keep shrinkage under 5%; hot tumble drying can exceed 12%.
- Moisture management
- Fabric is moisture-absorbent — cool for daily wear, but it won't wick sweat like a performance synthetic.
- Bamboo comparison
- Buyers switching from the older Solid Bamboo Trunk report the same fit; some question year-long wash durability.
- Fabric feel
- Buyers report the ECOVERO fabric is thinner, softer and cooler, yet less durable, than the old bamboo trunk.
- Support
- Buyers who switched from the older bamboo or cotton trunks report the ECOVERO version feels noticeably less supportive, with some describing the hold as low.
- Durability
- Returning buyers report pilling after washing and doubt a year of weekly washes; cold-water line-drying keeps ECOVERO shrinkage at 2-3%.
- Waistband
- Waistband feels slightly loose to some buyers, though designed not to squeeze.
- Inseam
- 3-inch leg avoids bunching under shorts but exposes inner thighs to friction if they touch.
- Pilling
- Some buyers report pilling after washing; cellulase detergents caused 3.2× more pilling on 92/8 viscose-spandex in 10 wash tests.
- Front panel
- Double-layer front panel provides opacity and maintains pouch shape over time.
- Flat seams
- Front and leg-hem stitching lies flat against the fabric, so no seam ridges press the skin.
- Stay-put
- 3-inch inseam and balanced leg openings keep trunks in place during activity.
- Leg line
- 3-inch legs end high, leaving no mid-thigh fabric to bunch or print a ridge under slim-fit trousers.
- Chafing
- For men whose thighs touch, the 3-inch leg exposes inner thighs to chafing during runs or lifts; a longer boxer brief is the fix.
- Colorway naming
- Each slash-separated color name is one multi-tone garment; Citrus/Bright Orange is the only high-chroma colorway.
- Sizing
- Navy/Midnight Blue alone has no SMALL and buyers report it runs smaller than other colors.
- Color accuracy
- Some buyers report the delivered colorway looks different from the online presentation.
- Sheerness
- The double-layered front panel stays opaque when stretched, though the color itself can still show through ultra-thin white or very light trousers.
- Camera use
- Buyers report the dyed colors look vivid on camera, making these trunks usable for costume or photoshoot work.
- Drying
- Buyers describe the fabric as thin, but air-drying takes over a day.
- Warm-weather layering
- 3-inch leg hides under athletic shorts or swim trunks and stays cool in heat.
- Sustainability
- ECOVERO fibre is EU Ecolabel-certified, FSC/PEFC sourced, and traceable via molecular marker after processing.
- Quick dry
- The fabric absorbs moisture and dries quickly for everyday wear, but it is not a technical athletic wicking fabric.
- Fly opening
- The double-layered front panel is a closed pouch with no functional fly or opening; it is designed for opacity and support rather than access.
- Sizing
- The trunk fits true to standard sizing; if between sizes, sizing up provides more comfort because trunks fit snugly around the thighs.
- Support level
- The trunk is fitted and close-to-body rather than a compression brief; its 4-way stretch and encased waistband keep it in place without squeezing.
- Waistband construction
- The waistband is an encased elastic style with no exposed branding, designed to prevent chafing and rolling.
- Material composition
- The trunk is 92% LENZING™ ECOVERO™ viscose and 8% spandex.
Product record
- Title
- 3" Solid Breathable Trunk Lenzing™ Ecovero™ Viscose
- Brand
- Le 31
- Price
- 20 CAD
- Availability
- In stock
- Rating
- 51 reviews
Image Analysis
2 images- 01

Product
Front view of a male model wearing a pair of black fitted trunk-style underwear showing waistband, front pouch seam, and leg openings.
- Overall silhouetteLow-rise trunk silhouette sitting below the model's natural waist with short leg length and a fitted close-to-body cut.
1 region
x 0.18 · y 0.58 · w 0.64 · h 0.30 (high) - WaistbandSmooth, elasticated waistband of the same black color as the body fabric, approximately uniform width and unstated visible branding.
1 region
x 0.18 · y 0.55 · w 0.64 · h 0.06 (high) - Front pouch and seamsContoured front pouch formed by a vertical center seam and curved stitching that defines the pouch area; seams are tonal and lie flat against fabric.
1 region
x 0.34 · y 0.64 · w 0.32 · h 0.20 (high) - Leg openings and hemShort, straight-cut leg openings with narrow folded hems and visible topstitching around the hemline.
1 region
x 0.20 · y 0.78 · w 0.60 · h 0.08 (high) - Fabric finishMatte, smooth knit fabric with no visible texture pattern and minimal sheen under studio lighting.
1 region
x 0.22 · y 0.62 · w 0.56 · h 0.24 (high) - Visible stitchingTone-on-tone stitching visible along waistband attachment, center pouch seam, and leg hems; thread matches fabric color.
1 region
x 0.24 · y 0.62 · w 0.52 · h 0.28 (high)
Other
Studio-shot cropped portrait of a male model from neck to mid-thigh against a neutral light-gray gradient background with soft, even lighting.
- Model pose and framingMale model stands facing forward with arms relaxed at sides; image cropped at neck and mid-thigh so only torso and upper legs are visible.
1 region
x 0.00 · y 0.00 · w 1.00 · h 1.00 (high) - BackgroundEven light-gray gradient backdrop, slightly darker at outer edges and lighter near center behind the model.
- Lighting and shadowSoft, diffuse studio lighting producing gentle shadows under the model and subtle highlights on skin; no harsh specular highlights on the fabric.
- Image cropCentered composition with symmetry around the vertical midline; top of head cropped out of frame.
Colors
deep black· main fabric and waistband#0E0E0E- Overall silhouetteLow-rise trunk silhouette sitting below the model's natural waist with short leg length and a fitted close-to-body cut.
- 02

Product
Rear view of a male model wearing solid black trunk-style underwear. Visible features include a flat elastic waistband, vertical center-back seam, smooth matte stretch fabric, and stitched leg hems.
- Silhouette and viewRear-facing trunk silhouette with mid-rise waistband and short leg length; garment covers the buttocks and upper thighs.
1 region
x 0.12 · y 0.58 · w 0.76 · h 0.28 (high) - WaistbandFlat elastic waistband about one seam-width tall, same color as the body fabric, sits horizontally across lower back.
1 region
x 0.12 · y 0.52 · w 0.76 · h 0.08 (high) - Center-back seamSubtle vertical seam running down the center of the rear panel from the waistband toward the crotch area.
1 region
x 0.47 · y 0.56 · w 0.06 · h 0.22 (high) - Leg hemsNarrow stitched hem finishing the leg openings on both thighs with flat, even stitching visible at each leg edge.
2 regions
x 0.20 · y 0.78 · w 0.20 · h 0.10 (high); x 0.60 · y 0.78 · w 0.20 · h 0.10 (high) - Fabric appearanceSmooth, tightly knit matte fabric with slight surface stretch and even color; no visible pattern or texture.
1 region
x 0.12 · y 0.58 · w 0.76 · h 0.28 (high) - Faint markingFaint embossed or printed marking at the upper center rear of the waistband panel; characters not legible in this image.Partial
1 region
x 0.47 · y 0.60 · w 0.06 · h 0.03 (medium)
Other
Studio rear-product shot on a neutral gradient gray background showing the model from head-top crop to upper thighs; soft, even lighting with minimal shadows.
- Shot compositionCentered rear-facing crop showing model from just above the shoulders to mid-thigh; model stands straight with arms relaxed at sides.
- BackgroundSmooth light gray gradient background that is brighter at center and darker at edges.
- Lighting and shadowSoft, even studio lighting producing gentle highlights on the shoulders and minimal hard shadows.
- Image qualityHigh-resolution, well-focused image with clear detail and even color rendering.
- Head cropTop of the model's head is cropped out of the frame.
1 region
x 0.28 · y 0.00 · w 0.44 · h 0.14 (high)
Colors
matte black· body#141414- Silhouette and viewRear-facing trunk silhouette with mid-rise waistband and short leg length; garment covers the buttocks and upper thighs.
Documents & Data
Customer Reviews
51 total51 reviews · out of 5
Not great, but decently comfortable!
The fabric looks cheap. . but it’s comfy!
Beau boxeur.
Belle qualité et belle couleur.
Beau tissus
Attrayant
Simple et efficace
Boxer confortable et joli
doux & confortable
doux & confortable
Matériel
Faible soutien
Boxeur
Le boxeur bleu la grandeur n’était pas exactement un médium comme décrit dans le boxeur , on aurait du inscrire petit car les autres couleurs était exacte
Boxeur
Confortable
Ok
Ok
Parfait
Doux, soyeux et minces!
Fit and look great!
These are very soft and fit very great. Love the hot colour and the look.
je recommande cet article
je recommande cet article
C est ok
C est ok
Bon achat
Confortable
Confortable.
Le boxeur est très confortable et était à rabais.
Parfait, tel que requis. Merci
Parfait, tel que requis. Merci
Baisse de qualité
Je m'ennuie de ceux en bambou ou en coton qui etaient beaucoup plus ferme. Ceux-ci sont moins confortable et offrent moins de soutien que les ancien modèles.
My husband’s favorite underwear
By far his favorite underwear. Loves the fabric and fit
Simple et efficace
Joli et confortable
BONNE ACHAT TRES CONFORTABLE
BONNE ACHAT TRES CONFORTABLE
Tissu de mauvaise qualité, un
Tissu de mauvaise qualité, un lavage et cela fait plein de moumoute
Great product
Great product
Confort
Composition et longueur parfaites
Mon préféré!
Super confortable!
parfait
parfait
Boxeur
Très confortable
aimes bien ce confort
aimes bien ce confort
A nice replacement to the Bamboo trunk
Bought as replacements to the previously made 'SOLID BAMBOO TRUNK' the fit is the same which is great, but I am unsure how they will measure up over the year of washing.
Très bon soutien
Mon favori
boxeur viscose
Belle qualité
Joli
Tres difficile à faire sécher….plus d un jour à l air naturel
Beau boxeur
Belle couleur. Pour le bas de Noël à mon fils.
Confortable
Mon conjoint les adorent…
Parfait
Parfait
so soft and the band
so soft and the band does not dig into the skin
Très satisfait
Très satisfait
Perfect Underwear
Fit true to size but comfortable and not hot.
J'apprécie le tissu et la
J'apprécie le tissu et la coupe
different colours, usual pants
suite me fine -
Différent de ce que l'on
Différent de ce que l'on montre.
What not to like ?
Soft fabric, good price, holds everything in place, elastic is not the "strangler" type (which I hate).
le boxeur court
excellent oui je le recommande
Good Quality
Very comfortable fit and well made.
Boxer
J’aurais. Aime plus de soutien
flashy
je trouve l'élastique de la taille un peu large
Comfy and a great colour
Using them for an upcoming photoshoot
Tres bon boxeurs
Ils me vont a merveille et de tres bonne qualiter!
Men’s trunk
Just what I hoped for
very comfortable
My husband is very happy with his new briefs, he find them very smooth and comfortable
Good pair
Exactly what I wanted. True to size
Less comfortable than the blue
Less comfortable than the blue one I had bought before and loved